Integrated heavy hydrocarbon and BTEX removal in LNG liquefaction for lean gases

A system for removing heavy hydrocarbons from a feed gas, the system comprising:

• a propane pre-cooling heat exchanger configured to cool an inlet gas;
• an absorber, wherein the absorber is configured to receive a top reflux stream and a second reflux stream within a top portion of the absorber, receive an expanded feed gas stream at a bottom portion of the absorber, and produce an absorber bottom product stream and an absorber overhead product stream;
• a stripper, wherein the stripper is configured to receive a feed liquid and the absorber bottom product stream and produce a stripper overhead product stream and a stripper bottom product stream;
• a pressure reduction valve configured to reduce a pressure of the absorber bottom product stream between the absorber and the stripper;
• and
• a compressor configured to pressurize the stripper overhead product stream from the stripper to form a compressed stripper overhead product stream, wherein the compressed stripper overhead product stream is configured to pass back to the absorber as the second reflux stream.

A system for removing heavy hydrocarbons from a feed gas, the system comprising:

• a propane pre-cooling heat exchanger configured to cool an inlet gas;
• an absorber section and a stripper section, wherein the absorber section is configured to operate at a pressure higher than the stripper section,
• wherein the absorber section comprises:
• an absorber, wherein the absorber is configured to receive a top reflux stream and a second reflux stream within a top portion of the absorber, receive an expanded feed gas stream at a bottom portion of the absorber, and produce an absorber bottom product stream and an absorber overhead product stream, and
• wherein the stripper section comprises:
• a stripper, wherein the stripper is configured to receive a feed liquid and a reduced pressure absorber bottom product stream and produce a stripper overhead product stream and a stripper bottom product stream;
• a pressure reduction valve configured to reduce a pressure of the absorber bottom product stream to produce the reduced pressure absorber bottom product stream;
• and
• a compressor configured to pressurize the stripper overhead product stream from the stripper to form the second reflux stream.